Combustion engines use breathing systems including induction systems for conveying induction gases to engine combustion chambers, and exhaust systems for carrying exhaust gases away from the combustion chambers. The breathing systems may also include exhaust gas recirculation (EGR) passages and valves to recirculate exhaust gases out of the exhaust system and back to the engine via the induction system.
Different valves may be used in such breathing systems to control the flow of gases in the exhaust system, air induction system, or EGR passages therebetween. But such valves typically have components that are sensitive to the flow of high temperature gases, such as actuators, shaft seals, bearings, position sensors, and plastic molded parts. Accordingly, current valves typically include relatively complex heat reduction measures such as liquid cooling, heat shielding, remote mounting of actuators, or expensive materials to achieve suitable durability at high temperatures.